[jackss]

I am trying to simulate a turbulent flow through a mitre pipe. I have tried both the hexahedral mesh and the tetrahedral mesh but i am not getting any good results. I am interested in the dynamic wall pressures , however, when i decrease the size of the tetrahedral mesh, the pressures are way too high, and when i decrease the size of the hexahedral mesh, the pressures are extremely low. I am using the LES model, velocity around 95m/s. can any one help .. i think i have tried nearly everything

[AlexanderZ]

as far as I remember, there is a limitation on max element size for LES

may be you may switch to simplified turbulent model, for instance k-w sst

you my know, that usually changing mesh is one of the way to verify your model, if there is significant difference in results with mesh to mesh, it means, model is not good enough and you should move to more refined mesh